弓形虫感染大鼠外周血T细胞亚群动态变化

目的观察弓形虫感染大鼠外周血T淋巴细胞亚群的动态变化。方法将58只清洁级SD成年大鼠随机分成9组,其中8组为实验组,1组为对照组,实验组每鼠腹腔注射2×105/LCF-11纤维素纯化的活弓形虫速殖子悬液2ml,对照组腹腔注射2ml生理盐水,并留4只为正常对照鼠。分别于弓形虫感染后1、3、7、14、28、35、42、60d时取大鼠外周全血,用流式细胞术检测外周血T细胞亚群CD3+、CD4+、CD8+百分比。结果弓形虫感染后3d、7d时,CD3+水平降至最低,但与正常鼠和对照鼠无显著性差异(P>0.05),至感染14d基本恢复至正常水平,此后再无明显变化。CD8+亚群水平在感染后3d、7d、14d时均显著低于正常水平(P<0.05),至感染后28d恢复正常水平。而CD4+亚群水平在整个感染过程中无明显变化(P>0.05)。CD4+/CD8+比例在感染后3d、7d、14d时显著高于正常鼠和对照鼠(P<0.05)。结论弓形虫感染影响大鼠外周血T淋巴细胞亚群比例,但可自行恢复正常。

Dynamic changes in the peripheral blood T cells in rats infected with Toxoplasma gondii

The dynamic changes in the peripheral blood T cells in rats infected intra-abdomianally with Toxoplasma gondii were observed by injecting 48 clean grade SD rats with 2 x 10~5 /L of cellulose-purified living tachyzoites suspended in 2 ml amount.The experimental rats were randomly divided into 8 groups, in which the control group of rats was injected intra-abdominally with 2ml of saline, and 4 rats remained to be used as the normal controls.Peripheral blood of rats was collected and the percentages of CD~+_3,CD~+_4 and CD~+_8 cells were determined by flow cytometry on day 1, 3, 7, 14, 28, 35, 42, 60 after infection. It was found that number of CD~+_3 cells in the experimental rats dropped to its minimal level at 3 th and 7 th days after infection, but no significant difference could be detected with those of normal rats and the control group of rats, and it almost turned to normal level at 14 th day after infection. The level of CD~+_8 cells in experimental rats was significantly lower than that of the control rats at 3 th, 7 th and 14 th days ,and it turned to normal level at 28 th day after infection.As to the level of CD~+_4 cells,there was no significant alteration in the whole course of infection. Ratio of CD~+_4/ CD~+_8 cells in experimental rats was significantly higher than that of the control rats on days 3, 7 and 14 after infection.It is concluded that the proportion of lymphocyte subsets can be alerted by the infection with T.gondii and it can recover spontaneously.